21731271842 has 16 divisors (see below), whose sum is σ = 38046240000. Its totient is φ = 9115244448.

The previous prime is 21731271833. The next prime is 21731271917. The reversal of 21731271842 is 24817213712.

21731271842 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 21731271796 and 21731271805.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16512467 + ... + 16513782.

It is an arithmetic number, because the mean of its divisors is an integer number (2377890000).

Almost surely, 2^21731271842 is an apocalyptic number.

21731271842 is a deficient number, since it is larger than the sum of its proper divisors (16314968158).

21731271842 is a wasteful number, since it uses less digits than its factorization.

21731271842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33026305.

The product of its digits is 37632, while the sum is 38.

The spelling of 21731271842 in words is "twenty-one billion, seven hundred thirty-one million, two hundred seventy-one thousand, eight hundred forty-two".